We propose to study the physicochemical properties of purified canine tracheal mucins and to elucidate the relationship between mucin structure and its rheological function and transport on the frog palate model. We also propose to study those variables affecting mucus transport on the frog palate. Mucus from normal dogs as well as those exposed to pharmacological agents on an acute basis will be studied. Also, we will initiate a program to extend these studies to human middle ear mucus obtained from patients with secretory otitis. The results of these studies should lead to a better understanding of the physicochemistry of mucociliary flow and its important role in obstructive pulmonary disease.